Search Results (43)

Research on shale reservoir characteristics and the controlling factors of gas content is critical for predicting shale gas “sweet spots”. Based on integrated geochemical, mineralogical, and petrophysical analyses, this study investigates the mineral composition of shale and the influencing factors of gas content in the Chang 7 Member of the Ordos Basin. The results show that (1) the shale clasts are mainly composed of quartz and feldspar, with the quartz contents in the range of 10.6%–29.7%, the feldspar contents in the range of 5.2%–38.2%, and the clay mineral contents in the range of 25.0%–70.5%. (2) The shale pore types include intergranular pores, granular dissolved pores and organic matter pores. The shale pores are mainly mesoporous and the pore sizes are mainly 6–9 nm with an average of 7.2 nm, accounting for 50% of the total pores population. (3) The shale kerogen maceral assemblage is composed primarily of the sapropel group, accounting for 77.2%–94.9% of the total macerals; vitrinite reflectance ranges from 0.80% to 1.13%, with a mean value of 0.83%. (4) The gas content of shale reservoirs is mainly controlled by temperature, pressure, total organic carbon (TOC) content, vitrinite reflectance, and reservoir physical properties. Among them, medium-to-large pores, TOC content, and pressure are the main controlling factors of shale gas content. The clay mineral content, vitrinite reflectance, and gas content constitute secondary controlling factors. Full article

The Upper Triassic Xujiahe Formation (T₃x) represents a critical terrestrial source rock system in the Sichuan Basin, exhibiting pronounced vertical and lateral heterogeneity. Previous stratigraphic subdivisions relied primarily on lithological correlations rather than a systematic sequence stratigraphic framework. This approach has led to significant inconsistencies in source rock evaluation. Furthermore, recent discoveries of large gas fields, coupled with data from newly drilled wells, necessitate a comprehensive reassessment of this system. In this study, we re-evaluate the geochemical characteristics and spatial distribution of these source rocks within a newly established sequence stratigraphic framework. This assessment utilizes a robust dataset comprising total organic carbon (TOC) content, Rock-Eval pyrolysis, and vitrinite reflectance (Ro) measurements. The results indicate that the source rocks of the New Member 5 (T₃x⁵) in the slope belt of Central Sichuan exhibit the highest hydrocarbon generative potential. These rocks are characterized by high organic abundance (with 40% of samples showing TOC ≥ 2.0 wt.%), are dominated by Type III and II₂ kerogen (humic–sapropelic), and have reached the mature to high-maturity stage (Ro ranging from 1.0% to 1.7%). Notably, the cumulative thickness of these high-quality source rocks reaches 100~150 m. Specifically, the T₃x⁵ intervals in the Qiulin and Tianfu areas are identified as the most favorable hydrocarbon-generating centers. This reassessment under the new stratigraphic division provides a refined theoretical basis for future exploration targeting the Xujiahe Formation in the Sichuan Basin. Full article

As solid biofuels gain increasing importance, the issue of rational management of the ash obtained from biofuel combustion is becoming increasingly relevant. This relevance will only increase in the future, since it is predicted that the main biofuel raw material will not be wood, but agricultural biomass with a high ash content. Biomass ash contains valuable nutrients, such as potassium and phosphorus, and therefore, it could be used for fertilization in agriculture. The concentration of nutrients in the ash can be made more balanced by granulating it with organic waste. This work presents the results of the environmental impact of using multi-crop biomass ash for fertilization of spring barley using the life cycle assessment method. Five scenarios were analyzed: (1) mineral fertilizer (MF), (2) non-granulated ash (NA), (3) ash and cattle manure pellets (ACM), (4) ash and sewage sludge pellets (ASS), and (5) ash and sapropel pellets (ASP). The results of the study show that all scenarios using ash for fertilization have a lower environmental impact compared with the scenario using only mineral fertilizers (MFs). The lowest carbon footprint (583.94 CO_2eq.) was determined for the ASP scenario. Normalization of the results showed that the ASS and ASP scenarios are the best from an environmental point of view, with the lowest environmental impact (24.90 and 24.60 Pt, respectively). Full article

Background: Balneotherapy (BT) has been proposed as a supportive intervention for post-COVID-19 musculoskeletal (MSK) and fatigue-related symptoms; however, comparative evidence across different BT delivery modes remains limited. This study aimed to evaluate the long-term effects of a BT-based treatment program on MSK health and related functional outcomes in individuals with a history of COVID-19. Methods: This secondary analysis was derived from a multicenter, randomized, controlled, single-blinded trial conducted from January to September 2023 across six Lithuanian medical spa centers. Participants with a self-reported history of COVID-19 and persistent multisystem symptoms were assigned to one of three BT modalities or a control group. Primary outcomes included MSK pain, muscle tension and spasm, handgrip strength, and trunk flexibility. Secondary outcomes included fatigue, sleep, quality of life, and analgesic use. Assessments were performed at baseline, post-treatment, and at three- and six-month follow-ups. The 2-week BT program consisted of daily sessions of light pool exercise, mineral baths, sapropel body wraps, and halotherapy. Data were analyzed using repeated-measures GLM in IBM SPSS Statistics (version 28.0). Results: Significant time effects were observed for MSK pain, muscle tension, spasms, fatigue, sleep disturbance, flexibility, and quality of life (all p < 0.05). Improvements occurred primarily within groups and were most pronounced immediately post-treatment, with partial maintenance at 3–6 months. Between-group differences were modest; however, ambulatory BT, inpatient BT, and BT combined with nature therapy demonstrated greater long-term improvements in several outcomes. Conclusions: BT was associated with beneficial changes across MSK and psychosocial domains in individuals recovering from COVID-19, although differences between BT modalities were limited. These findings support BT as a complementary component within multimodal post-COVID rehabilitation frameworks and highlight the need for further research on long-term maintenance and individualized treatment strategies. Full article

Background: Thalassotherapy, which combines seawater, marine mud, and maritime climate, has been traditionally used to support musculoskeletal recovery. Its thermal, biochemical, and mechanical properties may enhance tissue healing and modulate inflammation. This study aimed to evaluate the short-term clinical effects of a standardized two-week thalassotherapy program compared with conventional rehabilitation in post-traumatic patients. Methods: A matched controlled cohort study was conducted at the Corpore Sano Sanatorium, Techirghiol, Romania. Post-traumatic patients followed identical physiotherapy and hydrokinetic exercise routines; additionally, the thalassotherapy group received daily seawater baths, sapropelic mud applications, and exposure to marine aerosols. Pain levels, joint mobility, inflammatory status, and quality of life were assessed before and after the intervention. Adverse events and treatment tolerance were monitored throughout the study. Results: Patients undergoing thalassotherapy experienced more pronounced improvements in musculoskeletal function, pain relief, inflammatory balance, and quality-of-life outcomes compared with those receiving standard rehabilitation alone. Both interventions contributed to clinical progress, but the magnitude of change was consistently greater among patients treated with marine-based therapies. No adverse events or intolerance reactions were recorded, and all participants completed the program. Conclusions: Thalassotherapy may provide complementary short-term benefits in post-traumatic rehabilitation, enhancing functional recovery, symptom relief, and perceived well-being. However, due to the non-randomized design and short follow-up period, these findings should be interpreted cautiously. Further randomized studies with long-term outcomes are required to confirm the therapeutic role of thalassotherapy in modern rehabilitation practice. Full article

The Permian Kupferschiefer shale, a key stratigraphic unit within the Zechstein sequence of the Fore-Sudetic Monocline, represents both a metal-rich lithofacies and a potential source rock for hydrocarbon generation. This study presents a comprehensive geochemical characterization of selected Kupferschiefer samples obtained from the Legnica–Głogów Copper District (LGOM) and exploratory boreholes. Analytical methods included Rock-Eval pyrolysis, Py-GC/FID, elemental analysis, TG-FTIR, biomarker profiling, and stable carbon isotope measurements. Results indicate that the shales contain significant amounts of Type II and mixed Type II/III kerogen, derived primarily from marine organic matter with minor terrestrial input. The organic matter maturity, expressed by T_max, places most samples within the oil window. Rock-Eval S2 values exceed 60 mg HC/g rock in some samples, confirming excellent generative potential. Py-GC/FID data further support high hydrocarbon yields, particularly in samples from the CG-4 borehole and LGOM mines. The thermal decomposition of kerogen reveals multiple degradation phases, with evolved gas analysis identifying sulfur-containing compounds and hydrocarbons indicative of sapropelic origin. Isotopic compositions of bitumen and kerogen suggest syngenetic relationships and marine depositional settings, with samples from a North Poland borehole showing isotopic enrichment consistent with post-depositional oxidation. Kinetic parameters calculated using the Kissinger–Akahira–Sunose method demonstrate variable activation energies (107–341 kJ/mol), correlating with differences in organic matter composition and mineral matrix. The observed variability in geochemical properties highlights both regional and facies-dependent influences on the shale’s generative capacity. The study concludes that the Kupferschiefer in southwestern and northern Poland exhibits substantial hydrocarbon generation potential. This potential has been previously underestimated due to the unit’s thinness, but localized zones with high TOC, favorable kerogen type, and low activation energy could be viable exploration targets for natural gas. Full article

This paper analyzes the chemical evolution of Nuntași-Tuzla Lake (Romania) in the context of human intervention. Situated on the shore of the Black Sea, approximately 35 km north of Constanța, Nuntași-Tuzla Lake is part of the Razim–Sinoe Lake complex and a component of the Danube Delta Biosphere Reserve. This area has undergone significant transformations over the past 120 years: canalization of the connecting channels with the St. George arm, construction of polders for agriculture, closure of the connections to the Black Sea, and construction of the Razim–Sinoe irrigation system. After the irrigation system stopped working (around 2000), due to the isolation of the lake and the low flow coming from the two rivers that supply the lake with fresh water, it completely dried up in 2020. All these interventions have led to the ecological, hydrological, and chemical deterioration of the lake’s water. The main effects are (i) a decrease in water salinity and (ii) reduction in the production of sapropelic mud as the salinity decreases due to the influx of fresh water. Full article

An environmentally friendly and rational way of using wood waste is by introducing it into composite compositions. This paper investigates the use of wood chips from 10 to 60% for creating a thermal insulation composite. Prepared wood chips of various fractions were mixed with the sapropel/gypsum mixture. The composite with wood chips and a mixed sapropel/gypsum binder was hardened without thermal curing. Gypsum was added to absorb water from the sapropel and to give the composite its initial strength. Hydrated lime was used to improve the compressive stress of the binding material. The composite density varied from 400 to 1050 kg/m³, thermal conductivity varied from 0.0912 to 0.193 W/(m·K), and compressive stress varied from 0.2 to 7.9 MPa. The density of the composite and the studied properties depended on three factors: the ratio of sapropel to gypsum, the ratio of wood chips to binder, and the level of compaction. The content of sapropel/gypsum varied from 10 to 90%, the ratio of wood chips to binder varied from 0.5 to 1.5, and the compaction level varied from 16 to 40% according to the initial height of the mould. The main characteristics of the prepared composites with different sapropel/gypsum and wood chip ratios were determined. The density, compressive stress, and thermal conductivity results were statistically analysed. Full article

To investigate the methane adsorption characteristics in different types of kerogen, microscopic models for three kerogen types—sapropelic (Type I), mixed (Type II), and humic (Type III)—were developed in this paper based on the paradigm diagram. Using Materials Studio 2020 software, a combination of molecular dynamics and Monte Carlo adsorption simulations was employed to examine the kerogen from the molecular structure to the cellular structure, with an analysis rooted in thermodynamic theory. The results indicated that the elemental composition of kerogen significantly influenced both the heat of adsorption and the adsorption position, with sulfur (S) having the greatest effect. Specifically, the C-S bond shifted the methane adsorption position horizontally by 0.861 Å and increased the adsorption energy by 1.418 kJ. Among the three types of kerogen crystals, a relationship was observed among the adsorption amount, limiting adsorption energy, and specific adsorption energy, with Type I < Type II < Type III. Additionally, the limiting adsorption energy was greater than the specific adsorption energy. The limiting adsorption energy of Type Ⅲ was only 28.436 kJ/mol, which indicates that methane is physically adsorbed in the kerogen. Regarding the diffusion coefficient, the value of 0.0464 Ų/Ps in the micropores of Type I kerogen was significantly higher than that in Types II and III, though it was much smaller than the diffusion coefficient observed in the macropores. Additionally, adsorption causes volumetric and effective pore volume expansion in kerogen crystals, which occurs in two phases: slow expansion and rapid expansion. Higher types of kerogen require a larger adsorption volume to reach the rapid expansion phase and expand more quickly. However, during the early stage of adsorption, the expansion rate is extremely low, and even a slight shrinkage may occur. Therefore, in shale gas extraction, it is crucial to design the extraction strategy based on the content and adsorption characteristics of the three kerogen types in order to enhance shale gas production and improve extraction efficiency. Full article

There are two sets of hydrocarbon source rock formations developed in the Paleogene of the Zhu-1 Depression: the Wenchang Formation of semi deep lacustrine facies and the Enping Formation of lacustrine facies. Their basic geochemical characteristics, chemical structures, kerogen components, sedimentary paleoenvironments, etc., are not the same. High quality hydrocarbon source rocks are the basic conditions for oil and gas generation. This article comprehensively evaluates the key depression Paleogene hydrocarbon source rocks in the Zhu-1 Depression, and studies the development mechanism and controlling factors of hydrocarbon source rocks in this area, which is of great significance for understanding the development conditions, quality, and predicting potential high-quality hydrocarbon source rocks. After conducting rock pyrolysis, major and trace element analysis, and infrared spectroscopy experiments on the samples, it was found that the main source rock type of the Wenchang Formation is type II₁, which has a high HI value; the Enping Formation is mainly composed of II₂-III types with low HI values (with a small number of II₁ types), and the source rocks of the Wenchang Formation have a strong hydrocarbon producing aliphatic structure, with the sapropelic and shell formations being larger than the Enping Formation source rocks. By using methods such as CIA values, C values, and Mo-U covariant models, it can be concluded that during the Wenchang to Enping periods, the climate changed from warm and dry to cool and humid, and the overall environment was characterized by freshwater, weak oxidation weak reduction, and gradually decreasing paleo-productivity. At the same time, it was analyzed that the formation of organic rich sediments in the source rocks of the Zhu-1 Depression played an important role in the relative oxygen phase. The ratio of V/(V + Ni) to V/Cr can better indicate the redox environment of the water body and show a good correlation with TOC. Two sets of development models of source rocks controlled by paleooxygen phase were initially established, providing sufficient scientific basis for oil and gas exploration in the area. Full article

Sustainable development is one of the main directions of modern agriculture. First of all, sustainability in the agricultural sector can be achieved through the possible abandonment of traditional mineral fertilizers. Many decades of using these fertilizers have led to the degradation of arable soils and to soil and environmental pollution. As a result, this causes reductions in yields and the environmental quality of agricultural products and affects the health of the population. An alternative to traditional mineral fertilizers may be the use of innovative organomineral fertilizers obtained from local resources. These include manure, humus, compost, sediments, etc. In recent years, fertilizers obtained from the sapropels of the bottom sediments of lakes have become widespread. Their distinctive feature is the environmental friendliness and completeness of the content of chemical elements and substances necessary for the development and growth of plants. In addition, the methods of obtaining and applying these fertilizers allow us to talk about their effectiveness in use. The range of applications of these fertilizers is diverse, from use in the form of a dry extract applied directly to the soil to the use of liquid suspensions used at various stages of processing and from pre-sowing seed treatment to watering and spraying plants at different periods of vegetation. Moreover, an important aspect is the research work on the variational use of sapropel fertilizers on different crops, with different methods of production and concentrations and at different stages of processing. This publication contains the results of a study of the effect of the obtained innovative sapropel fertilizer on productivity, wheat grain quality, and economic efficiency (Triticum aestivum L.). To identify the optimal concentration of sapropel extract, laboratory studies were carried out to determine the germination energy and germination of wheat seeds of different varieties when they were soaked in various concentrations: 0.4, 0.8, 1.2, 1.6, and 2.0 g/L. The best indicators of germination energy and germination of wheat seeds during treatment with the extract were obtained at a concentration of 1.2 g/L. The research was conducted at an accredited variety testing laboratory. A field experiment was conducted in the fields of the agrobiological station of North Kazakhstan University named after Manash Kozybayev. The treatment of the seeds was carried out by soaking them in sapropel extract to evenly distribute the substance. The scheme of the field experiment included the option of using foliar treatment with a solution of sapropel extract at the tillering stage. As a result of the application of the obtained extract in the field, environmental and socio-economic efficiency was noted. The conducted field studies note its positive effect and effectiveness on the morphological, qualitative, and quantitative indicators of the wheat harvest. In the areas where wheat seeds were pretreated, as well as where foliar treatment with the resulting sapropel suspension was carried out, the best yield indicators were revealed. In these variants of the experiment with pre-sowing and pre-sowing and foliar treatment with the sapropel extract solution, the yield was 3.63 and 3.81 tons per hectare, respectively. The introduction of sapropel extract at the stage of seed treatment before sowing, as well as foliar processing of wheat at the tillering stage, will increase the efficiency and profitability of the agricultural industry and obtain a synergistic effect in the form of socio-economic efficiency and environmental safety of production. In our opinion, this will contribute to the development of sustainable agriculture and the production of environmental products. Full article

By systematically analyzing the natural gas composition, carbon isotopes, and source rock characteristics in the Yongfeng sub-sag of the Bogda Mountain front belt, natural gas characteristics were determined, and the genetic types and sources of natural gas were investigated. The research results indicate that methane is the main component of natural gas in the Yongfeng sub-sag, with low levels of heavy hydrocarbons and a high drying coefficient. These characteristics make it dry gas, which refers to natural gas with a methane content of over 95%. The ethane carbon isotope δ¹³C₂ of natural gas is −28.5‰ and belongs to oil type gas. The methane carbon isotope δ¹³C₁ of natural gas is −58.6‰~−59.4‰, has a relatively depleted methane carbon isotope value, shows significant differences from the surrounding natural gas methane carbon isotope, and belongs to the category of biogenic gas. The Permian Lucaogou Formation is the main source rock in the study area, with good organic matter abundance. The microscopic components of kerogen are mainly composed of sapropelic formations and the organic matter type is I–II₁. The source rock has a high maturity and has reached the mature stage, mainly consisting of oil and wet gas. The ethane carbon isotope of natural gas in the Yongfeng sub-sag shows as oil type gas, which is consistent with the kerogen type of the Lucaogou Formation source rocks, indicating that the natural gas mainly comes from the Lucaogou Formation source rocks. Based on comprehensive data and information on natural gas composition, carbon isotopes, and burial history of the source rocks, it is believed that some of the crude oil generated from the Lucaogou Formation in the early stage underwent biodegradation due to tectonic uplift, resulting in biogenic methane and the formation of crude oil biodegraded gas. Full article

Greece is expanding its energy grid system with submarine power and fiber optic cables between the mainland and the Aegean Sea islands. Additionally, pipelines have been installed to support natural gas facilities, and sites are being demarcated for the development of offshore wind parks. The above developments have necessitated extensive geotechnical surveying of the seabed; however, the survey data cannot be accessed for academic inspection or for desktop studies of future developments. This is further hindered by the limited geotechnical information in the Aegean and Ionian Seas. This review examines the existing information concerning the geotechnical behavior of the surficial sedimentary layers, including certain challenges associated with geotechnical sampling and CPTu interpretation. Certain prospects are discussed regarding marine geotechnical research in Greece, with examples from other European countries. The marine geotechnical data in Greece include geotechnical analyses of sediments cores and slope stability estimations, which are commonly associated with the seismic profiling of unstable slope areas. Underlying mechanisms of slope failure have mainly been attributed to the interbedded presence of weak layers (e.g., sapropels, tephra and underconsolidated sediments), the presence of gas and the cyclic loading from earthquake activity. Due to the limited geotechnical information, geological studies have contributed considerably to describing the distributions of gravity-induced events and lithostratigraphy. Within this context, a geological/geotechnical database is suggested where data can be collated and utilized for future studies. Full article

Multiple types of reservoirs, including volatile oil reservoirs, condensate gas reservoirs, and dry gas reservoirs, have been discovered in ultra-deep layers buried at depths greater than 7500 m. Understanding the genetic types of natural gas is of utmost importance in evaluating oil and gas exploration potential. The cumulative proved reserves of the super deep layer in the Shuntuoguole low uplift area of the Tarim Basin exceed 1 × 10⁸ t (oil equivalent). The origin, source, and accumulation characteristics of natural gas still remain a subject of controversy. By analyzing the composition and carbon isotope of natural gas, a detailed investigation was conducted to examine the unique geochemical and reservoir formation characteristics of the Ordovician ultra-deep natural gas within different fault zones in the middle region of the Shuntuoguole low uplift. It was determined that most of the natural gas in this area is displaying a characteristic of wet gas with a drying coefficient ranging from 0.41 to 0.99. The carbon isotope composition of methane in the gas reservoir shows relatively light values, ranging from −49.4‰ to −42‰. The carbon and hydrogen isotopes of the components are distributed in a positive order. The natural gas is oil type gas, which is derived from marine sapropelic organic matter and has a good correspondence with the lower Yuertusi formation. The maturity of natural gas in Shunbei No. 1 and No. 5 fault zones is about 1.0%, which is the associated gas of normal crude oil, while the maturity of No. 4 and No. 8 fault zones is higher than 1.0%, which is the mixture of kerogen pyrolysis gas and crude oil pyrolysis gas. The variations in the drying coefficient and carbon isotope composition of the natural gas provide evidence for the migration patterns within the Shuntuoguole low uplift central region. It indicates that the Shunbei No. 5 and No. 8 fault zones have likely migrated from south to north, while the No. 4 fault zone has migrated from the middle to both the north and south sides. These migration patterns are primarily controlled by high and steep strike-slip faults, which facilitate the vertical migration of natural gas along fault planes. Consequently, the gas accumulates in fractured and vuggy reservoirs within the Ordovician formation. Full article

Research has been conducted on the development of an innovative organomineral fertilizer based on local lake resources as a stimulator of germination and growth of crops, as one of the factors in achieving the goal of environmental sustainability. The results obtained are based on the environmental friendliness of the technology, increasing yields, and obtaining environmentally friendly products. This, in turn, will not only save mineral resources but also make it possible to use the resources from the bottom sediments of local lakes, and their rational extraction will contribute to the sustainable development and restoration of lake ecosystems. This article highlights the results of laboratory and field studies on the use of sapropel extract at the stage of pre-sowing seed treatment obtained by extraction of bottom sediments from lakes in Northern Kazakhstan. Solutions of aqueous alcohol extract of sapropel extract with concentrations of 0.4, 0.8, 1.2, 1.6, 2.0 g/L and table beet seeds (Beta vulgaris L.) of Bordo 237 variety were used as objects of research. Statistical analysis of laboratory experience data, based on the determination of germination energy and seed germination, allowed us to identify the optimal concentration of sapropel working solution for pre–sowing seed treatment—1.6 g/L. The index of germination energy and germination of seeds during pretreatment with sapropel extract of this concentration was 40% and 50%, respectively. This contributed to an increase in germination energy by almost 2 times and in seed germination by more than 40%. Pre-sowing treatment of seeds with sapropel extract at a concentration of 1.6 g/L in a field experiment contributed to the improvement of biometric indicators of beet fruits, such as diameter, length, and weight. The results of the data on fetal weight of the experimental variant compared with the control were 27% higher, and they were 26% and 32% higher compared with other experimental variants. In the experimental group, the highest yield index was also established, which is 2.15 times, or 53%, higher than the control, which emphasizes the effectiveness of pre-sowing seed treatment with the resulting sapropel suspension. A patent of the Republic of Kazakhstan was issued for the method we developed for obtaining a sapropel product for pre-sowing treatment of seeds: “A method for obtaining a sapropel product for pre-sowing treatment of vegetable seeds”. The research presented in the article confirms its effectiveness. The use of this product in pre-sowing seed treatment reduces the number of agrotechnological operations and costs, which makes this method more efficient and economically beneficial for the agricultural industry. Thus, the principle of food security will be implemented, contributing to the preservation of sustainable development and having a positive impact on the health of the population. Full article